Fusible boiler-check plug



J. A. MASCHO' FUSIBLE BOILER CHECK v PLUG Filed April 30. 1925 Q cfk'zrzesfl /asah INVENTOR w v I I fzz ATTORNEY Patented Aug. 30, 1921' nmrso stares rATEN r o FIcE.

JAMES A. MASGHO, or DALLAS, TEXAS.

rUsIrLE BOILER-CHECK PLUG;

- Application filed April 30, 1925. Serial No: 26,842.

This invention relates to new and useful improvements in safety fuse plug devices.

In the present construction of steam bo lers there is inserted int'he crown sheet of the fire-box a babbitt-lilled or fusible plug" arranged so that when the danger pointor low water stage is reached in the boiler the fusible-material will be melted by the heat, releasing the water and steam, thusextinguishing the fire and preventing an explosion. the fusible material has melted and the explosion averted, to sealup the opening in the plug by a wooden substitute filler or peg of wood then wait until the boiler has cooled :sutliciently before refilling it, which is also in this case done by means of a hand pump. The placing of the substitute plug or filler. is hazardous and dangerous on account of escaping steam and hot water.

It is the object of the present invention to provide an improved means in connection with thefusib-leplug to close the open- With the above objects in view theinven-v tion will be better and more clearly understood by reference to the following detailed description in connection with the accompanying drawings, and wherein:

Figure 1. is an elevation of a device constructed in accordance with my invention,

Figure 2 is a vertical sectional view'taken on the line 22 of Figure 1,

Figure 3 is a cross-sectional View taken on line 38 of Figure 2,

Figure 4 is a plan view,

Figures 5 and 6 are detail perspective and side views of parts of the device removed from the same, I v

Figure 7 is a partial vertical sectional. view of another form of the invention,

and

It is now the common practice, after mg made by the melting of the fusible Figure 8 is an underside view of the plug,

Figure9 is a partial side view-of said plug.

In carrying out the invention there is provided a; substantially cone-shaped". cylindrical shell 1, screw-threaded as shown in Figure 1, the lower part 2 being shaped to receivedj a wrench. The interior of the shell lisalso threaded-to receive ahollow plug 3, also provided with a square or'hex agonal head 4;.

The plug 3 represents a formof plug or-' 7? .dmanly employed and has an axial bore 3" filled with a babbitt core or other fusible material 5 from end to end.v This plug isseated in theshell l, asillustrated in Figure 2. The shell has a spider 6 dividing .the chambers? and Sand is apertured to receive the stem 9 of a valve 10, the latter having spaced vertical guides 11-.Il.

'Above the chamber 8 and communicating therewith is a passage 12 and above this is a valve seat 13 for the valve 10. This valve and stem are clearly shownin Figure 6 and 1n F1gure 5 1s a vlew of a support ng memher or bar 1 which is screwed onto the lower end of the valve stem to support the 1 valve 1n inoperative position as 1n Figure 2;. -The bar has depending end fingers 1 l- 14 which rest upon the top of the plug 3-,

so that the bar will not close the bore 8.

In Figures 7, Sand 9is shown another form;-o f the device. In this form a T- shaped key 16 is molded in the core 5 and has a horizontally directed cross-bar- 16".

The ends of this bar extend through slots 3 in the head 4, see Figure 9. The slots eliminated but its equivalent, a nut 9 may be placed on the end of the stem 9 to limit upward movement thereof. Thus the stem 9 may be released, after the core has fused, and the valve seated by moving the ends 16 of the key 16-to register with the shanks 4 of the'slots 3 in the head 4:

In the operation of the device, the upper end of the shell l having been screwed into the crown sheet (not shown) from the firebox, when the water is at the danger line the fusible core 5 will melt and permit the Water and steam to pass down through the passage 12, chambers 8and 7 and bore 3 andthus extinguish the fire. When this occurs the plug a, by means of a long handle vrench or tongs, is unscrewed, whereupon the bar 14: may fall and the valve 10- will rest in the seat lB-and thus prevent further escape of steam and water into the fire box;

The'boiler may now be refilled with water and a new plug inserted which Wlll cause the valve to assume its normal lnoperative posi- J.'

blOll.

In the form shown in Figures 7, 8 and 9,. the li -shaped key 16 may be easily reached when the core 5 has melted and the ends 16* of the lrey l6 moved to register with the slots" 4*, -thus allowing the key to drop out, whereby the valve 10 will be seated.

Various changes and modifications may be made within the scope of the'appended *claims.

lVhat 1 claim, is:

1. In a boiler safety fuse plug device, a

' shell screw-threaded for inserting in a vertical position in a boiler, said shell having a bore and a valve seat at the upper end of said bore, a valve for engaging said seat normally supported above it, 111621118 for supporting said valve inv its normal position, a plug Screw-threaded into the lower end of the shell, 7 said plug having a bore extending therethrough, and a fusible core in the bore of the olu the alu 'carr in means for.

b, D O

supporting the valve in its normalposition after the core has melted.

2. In a boiler safety fuseplug device, a

shell screw-threaded for insertion in averti- V cal position'in a boiler, said shell having a the shell below the spider and having a fusible core, the shell and parts carried there by being bodily removable from the boiler.

8. In a boiler safety fuse plug device, a shell screw-threaded for insertion in a vertical position in a boiler, said shell having a bore and a valve seat at the upper end of the bore, a spider extending across the bore, a valve normally held above the seat of the shell, a stem depending from the valve and extending through the spider, means on the lower end of the stem engaging the spider.

for limiting the upward displacement of the valve stem, and a plug screw-threaded into the lower end of tie shell below the spider and having a fusible core, theplug carrying means for-supporting the valve in its normal,

position after the core has melted.

In a boiler safety fuse plugdevice, a shell-screw-threaded for inserting in a vertical position in a boiler, said shell having a bore and a valve seat, at the upper end of said bore, a valvefor engaging said seat normally supported above it, means forfsu'pporting said valve in its normal position, and a plug removably mounted in the lower end i of the shel and having a fusible'core, the

valve supporting means supporting the valve" in its open position after the fusing-of the core of the plug andbeing'removaoly supported in the plug so as to be'reinoved for closing the valve. i

5. In a boiler safety fuseyplug device,a

shellscrew-threaded for insertion in a vertical position in a boiler, said shell having a bore and a valve seat'at the upper end of said bore, a valve for engaging said seat, a stern depending from the valve, a plug removably mounted in the lower end ofthe shell and having a fusible core, and a key removably mounted in the plug and supporting the valve stem. I

In testimony whereof I have signed my name to this specification.

JAMES anirsGno. 

